Pesticides are used to control pests in areas such as crops, homes, and food storage areas. However the large scale use of pesticides, particularly in the second half of the twentieth century and early twenty first century, has resulted in significant concerns with respect to the environmental impact, increased resistance against pesticides in the pest populations, as well as toxicity to non-target organisms, including humans. Controversial is for example the use of polychlorinated hydrocarbons, such as DDT, as they persist for extended periods of time in the environment and are harmful for example to fish and birds of prey. Another class of pesticides, methylbromides, in addition to being toxic to the human nervous and respiratory system, poses damage to the stratospheric ozone layer, as a result of which governments in many jurisdictions have been severely restricting the use of methylbromides. Other widely used efficacious pesticides include organophosphates and carbamates, and while these compounds decompose more rapidly in the environment, they are still considered highly toxic.
One alternative is the use of pesticides obtainable from natural sources, also referred to in the art as biopesticides. These biopesticides are prepared from sources such as plants which frequently comprise natural defenses against insects and other pests. Glucosinolates which are ubiquitously found within the mustard plant family (also alternatively known to the art as “Cruciferae” or Brassicaceae”), which includes for example, mustard and rapeseed, act as pesticides in many plants. The pesticidal efficacy of mustard plant material is attributable to glucosinolate breakdown products, including allyl thiocyanate and allyl isothiocyanate, rather than glucosinolates themselves. These glucosinolate degradation products are formed following an enzymatic reaction involving enzymes endogenously present in mustard plant material.
Pesticide products based on mustard plant material are known to the prior art. US Patent Application 2008/0182751, for example, discloses the use of mustard plant material to control plant pests, including insects, and U.S. Pat. No. 5,717,056 teaches the use of mustard bran to control soil pests. The use of mustard meal to control plant pests is disclosed in Brown, J. and Morra, M. J, 2005, Subcontract Report National Renewable Energy Laboratory NREL/SR-510-35254. Purified products and organic extracts obtainable form mustard plants for use of the treatment of pests are also known to the prior art. In this regard U.S. Pat. No. 7,087,553 discloses a process for eliminating unwanted organisms in agriculture comprising the co-application of mustard oil in water and a solution of phosphorus in water. U.S. Pat. No. 6,545,043 teaches methods for suppressing target pests using a composition comprising a purified glucosinolate breakdown product obtainable from mustard plants. Mustard meal based glucosinolate products have been demonstrated to exhibit inhibitory effects against arthropods, as well as weeds, fungi and bacteria (see: Brown, J. and Morra, M. J, 2005, Subcontract Report National Renewable Energy Laboratory NREL/SR-510-35254).
Notwithstanding the foregoing, the potency of the mustard plant material derived pesticides known to the prior art is lower than desirable, allowing for limited pest control, and requiring the use and application of substantial volumes of mustard plant material in order to control the pests.
There therefore still are significant shortcomings in mustard plant material based formulations capable of controlling pests that are known to the prior art. In particular, there is a need for a more potent pesticide prepared from mustard plant material, allowing for the application of less mustard plant material and less expensive pesticide formulations.